We have had very few reported security issues with Warmshowers.org, but with a large user base, they will happen from time to time. Warmshowers.org is just a mechanism to help like-minded users connect with each other, and has no way to protect you or guarantee the "niceness" of users. Therefore, you'll have to use your own head and create your own rules for dealing with users who contact you.

You must use your own good sense in dealing with users who contact you or stay with you (or with whom you stay).

Here are a few things that we typically say in email to users who are concerned with their personal security (when participating in the Warmshowers.org community):

• You are responsible for your own personal safety and security, both as a traveler and as a host. You must make your own wise choices.
• You are never under any obligation to let a Warmshowers.org user  into your home if you feel uncomfortable. Sometimes it may be the context of their initial email requesting hospitality, or it may be that they have written very little about themselves in their account. Always remember that your safety and that of your family is of paramount importance.
• If a Warmshowers.org user shows up at your door and asks for a place to stay without prior communication you shouldn't feel bad about saying "no" and pointing them towards a nearby motel or campground. This is your call, but you should feel no obligation to host anyone who shows up without making arrangements in advance.
• When a user contacts you, take a look at their Warmshowers.org profile. The more information you see there, the better. Many travelers have a website as well. Follow the link from the profile to their website, and you'll be able to have more of a sense of who they are. Also, on their profile you'll see whether they have received (or given) any recommendations (at the bottom of the profile page).
• You are not required to list any more than your hometown and state/country in your account with respect to your personal contact information. So do not list your home address or any phone numbers if you are concerned about this. You can exchange this information with prospective Hosts after you have established a rapport and feel comfortable with them. If you do not list your street address, please use the "set map location" tab to set your location on the map so it's at least near your home. That way cyclists will know whether you're actually on their route.
• If you would like to restrict who you are willing to host you may write that into the "about me" part of your account. For example we have some female users who only want to host other ladies or perhaps couples -- but not single men. Some users will not host if the prospective guest does not have any recommendations or references. Feel free to write things like this into your account.
• If you have agreed to host another Warmshowers.org user and are worried about it, consider inviting a friend or neighbor over around the time you expect the user to arrive. Ask them to stick around until you feel comfortable with the user you have agreed to host.